Lockable transportation rack for storing and shipping sheet materials

ABSTRACT

A “harp rack” for the storage and shipping of sheet material modified so that the stringers are rotatably mounted for simultaneous rotation relative to a supporting base and frame between a locking position and a release position, the stringers each have locking vanes disposed on opposite sides which terminate in a glass engaging stopper such as rubber.

FIELD OF INVENTION

This invention relates to racks for packaging, storing and transportingsheet material, particularly glass, but also metal, plastic, marbleplates, windows and doors.

BACKGROUND OF THE INVENTION

Glass panes are usually produced, cut to specific sizes required by theend user and shipped as lites in pallets which may be boxed in woodencases. Glass lites are also moved around on factory floors using wheeledpallets known as “harp racks” which consist of steel rods covered withplastic sleeves, mounted to a frame and usually inclined at an angle ofapproximately 50° to separate glass panes supported on a slotted base.The harp racks are available in many configurations and can have one ortwo levels or decks disposed one above the other, optionally with aninner string set of shorter rods to accommodate and separate glass paneshaving smaller dimensions and an outer string set of longer rods toaccommodate and separate larger glass panes. While the harp racks may beused for transportation off-site by using plastic shrink-wrap toimmobilize the glass lites on the racks, this is not a satisfactorysolution and harp racks are not generally considered suitable forshipping glass lites to another location.

An object of this invention is to provide means for securing sheetmaterial in a harp style rack so that the same rack may be used formoving the sheet material at the pick-up and delivery locations withoutany intermediate loading and unloading for shipping between locationsand without the need for plastic shrink wrap or other securing devices.

SUMMARY OF THE INVENTION

In accordance with this invention, there is provided a so-called “harprack” in which the stringer assembly is modified so that the stringersare rotably mounted for simultaneous rotation relative to a supportingbase and frame between a locking position and a release position, thestringers each having transversely extending locking means disposed onopposite sides and terminating in a glass engaging stopper such asrubber.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be more clearly understood, a preferredembodiment is described below with reference to the accompanyingdrawings, in which:

FIG. 1 is a perspective view of a double level, double string lockingharp rack made in accordance with the invention;

FIG. 2 is a top plan view of a glass pane trapped between a pair ofstringers rotated into a locking position;

FIG. 3 is a top plan view similar to FIG. 2 showing the stringersrotated into a release position;

FIG. 4 is an exploded view showing a stringer assembly and a frame forthe locking harp rack;

FIG. 5 is a perspective view showing the stringer assembly of FIG. 4 inan assembled configuration; and

FIG. 6 (drawn to a larger scale) is a side elevation of a portion of thestringer assembly of FIG. 5.

DESCRIPTION OF PREFERRED EMBODIMENT WITH REFERENCE TO DRAWINGS

A locking harp rack made in accordance with the invention is generallyindicated by reference numeral 20 in FIG. 1. Like prior art harp racks,the harp rack 20 has a base 22 which has a series of spaced parallelgrooves 24 that extend along the length of the base 22 to support sheetsof glass and the like (not shown). The base 22 is conveniently made ofsynthetic plastic material such as high density polyethylene which canbe cut to form the grooves 24. The base 22 is supported in a frame 26 onlocking caster wheels 28. An upper deck 30 similar to the base 22 isvertically disposed above the base 22 to accommodate a second tier ofsheets or glass panes.

A plurality of stringers 32 are mounted to the frame 26 and are spacedfrom each other along the width of the base 22 between each of thegrooves 24 to form a lower string set 34 inclined at about 50° betweenthe base and a horizontally extending mounting channel 38 forming partof the frame 26. An upper string set 36 is inclined at a similar anglebetween the upper deck 30 and a respective horizontally extendingsupport 40. In the embodiment illustrated, the base 22 and the upperdeck 30 each support an inner string set 42, 44 to accommodate sheets orglass panes having smaller dimensions. The inner string sets 42, 44 areconventional in nature and consist of metal rods fixed to the frame andcovered with a synthetic plastic sleeve.

The stringers 32 in the lower string set 34 have been modified inaccordance with this invention to be rotatable relative to thehorizontally extending support 38 and the base 22 between a lockingposition and a release position using an operator handle 46.

The construction of the stringers 32 will now be described withparticular reference being made to FIGS. 2, 3 and 6. Each stringer 32has a pair of metal rod terminations 48 fitted and welded to alongitudinally extending central metal plate 50. The metal plates 50have a narrow width of z-shaped cross-section (FIGS. 2, 3) that definesa pair of transversely extending locking vanes disposed on oppositesides of the stringers 32. The free edges of the metal plate 50 arecovered by a rubber stopper 52 consisting of a narrow strip of rubbersheet glued to opposite sides of the metal plate so that only softresilient material will engage a glass sheet 54 received in a groove 24.The lower rod termination 48 is received in a journal-bearing formed ina bottom guide plate 56 (FIG. 4) disposed in the base 22.

Rotation means for rotating the stringers 32 will now be described withreference to FIGS. 4, 5, 6. The upper rod terminations 48 traverse themounting channel 38 forming part of the frame 26 through a series ofrespective apertures 39 formed therein and are received in respectivejournal bearings formed in an upper rod guide 58 fixed to the channel38. The upper rod terminations 48 each have a respective spring arm 60extending transversely to the axis of the rod terminations 48 whichengages a sliding plate 62.

The sliding plate 62 is slidably mounted in the channel 38 through threesliding guides 64 spaced across the width of the channel 38 and having agroove for slidably receiving the sliding plate 62. Respective pins 66traverse the sliding guides 64 and are received in corresponding slots68 formed in the sliding plate 62. The upper edge of the sliding plate(as drawn) is castellated or notched to receive a respective spring arm60 and a spring biasing coil 70 in each notch whereby contact ismaintained between the sliding plate 62 and the spring arm terminations60.

The external operator handle 46 is pivoted to the frame at pivot pin 72and carries a connecting rod 74 which is coupled to one end of thesliding plate 62 so that rotation of the handle 46 causes translation ofthe sliding plate 62, as indicated by arrow 76. It will be noted thatthe connecting rod 74 is threaded so that its length may be adjusted fortighter or looser locking force. Meanwhile, downward rotation of theoperator handle 46 from the release position (as drawn) will cause thehandle 46 to traverse the center of rotation of pivot pin 72 and come torest in an over-centre locking position.

In use, such rotation of the operator handle 46 to pull the slidingplate 62 to the left (as drawn) allows the spring coils 70 to expand andbear against the spring arms 60, thereby rotating the stringers 32 asindicated by arrow 78 in FIG. 2 to cause the stoppers 52 to firmlyengage the glass sheet 54 at substantially right angles on oppositesides thereof.

Each glass sheet 54 is thus trapped between a pair of stringers 32 eachof which makes line contact with the glass sheet 54 along the length ofthe stopper 52. Release of the glass sheets as shown in FIG. 3 can onlybe achieved by positively moving the operator handle 46 upward to bringthe handle over the center of rotation of pivot pin 72 and to push thesliding plate 62 against the spring arms 60 so that the spring coils 70are compressed (as drawn). Pushing against the spring arms 60 causes thestringers 32 to rotate in the opposite direction as shown by arrow 80 inFIG. 3 thereby bringing the stringers to a release position where thestoppers 52 are spaced from the glass sheet 54.

It will be understood that several variations may be made to theabove-described embodiment of the invention within the scope of theappended claims, as will be apparent to those skilled in the art. Inparticular, the shape and configuration of the stringers may be variedto have for example, a plurality of stoppers each making point contactwith the sheet and the mechanism for rotation of the stringers may besubstituted by others, such as, for example, a rack and pinion means fortranslating a carriage to rotate the stringers. Other such variationswill be apparent to those skilled in the art and will be consideredmechanical equivalents to the embodiment described.

1. In a transportation rack for storing and shipping sheet material, therack having a base coupled to a frame, the base having a width and alength, the frame having at least one horizontally extending supportvertically spaced from the base, a plurality of stringers spaced fromeach other along the width of the base and extending between the said atleast one horizontally extending support and the base, the stringersbeing adapted to separate sheets material supported by the base, theimprovement in which the stringers are rotatably mounted for rotationrelative to the support and the base between a locking position and arelease position, the stringers each having a pair of transverselyextending locking vanes disposed on opposite sides thereof andterminating in a glass engaging stopper, and rotation means forsimultaneously rotating the stringers to bring the stoppers into and outof engagement with any sheet material supported on the base.
 2. Atransportation rack according to claim 1 in which the stoppers are madeof a resilient material.
 3. A transportation rack according to claim 2in which the stoppers are made of synthetic plastic material or rubber.4. A transportation rack according to claim 1 in which the locking vanesare integrally formed into a Z-configuration symmetrically disposed on arotation axis for the stringers, the stoppers being mounted to free endsof the vanes so that, in use, the stoppers will engage the sheetmaterial at substantially right angles.
 5. A transportation rackaccording to claim 1 in which the rotation means is disposed in saidhorizontally extending support and the base has a journal-bearing forrotation support of the stringers.
 6. A transportation rack according toclaim 1 in which the rotation means is actuated by an external operatorhandle, the operator handle being pivotable between said releaseposition and said locking position, where it is locked by an over-centrelocking lever.
 7. A transportation rack according to claim 1 in whichthe rotation means has an external operator handle for translating asliding plate that engages the stringers between said release positionand said locking position, the stringers each having respective springarm terminations for engaging the sliding plate, spring biasing meansbeing disposed between the spring arm terminations and the sliding plateto maintain contact between the sliding plate and the spring armterminations, whereby translation of the sliding plate causes thestringers to rotate.
 8. In a transportation rack for storing andshipping sheet material, the rack having a base coupled to a frame, thebase having a width and a length, the frame having at least onehorizontally extending support vertically spaced from the base, aplurality of stringers spaced from each other along the width of thebase and extending between the said at least one horizontally extendingsupport and the base, the stringers being adapted to separate sheetsmaterial supported by the base, the improvement in which the stringersare rotatably mounted for rotation relative to the support and the basebetween a locking position and a release position, the stringers eachhaving transversely extending locking means terminating in a glassengaging stopper, and rotation means for simultaneously rotating thestringers to bring the stoppers into and out of engagement with anysheet material supported on the base.
 9. A transportation rack accordingto claim 8 in which the stoppers are made of a resilient material.
 10. Atransportation rack according to claim 8 in which the stoppers are madeof synthetic plastic material or rubber.
 11. A transportation rackaccording to claim 8 in which the rotation means is disposed in saidhorizontally extending support and the base has a journal-bearing forrotational support of the stringers.
 12. A transportation rack accordingto claim 8 in which the rotation means is actuated by an externaloperator handle, the operator handle being pivotable between saidrelease position and said locking position, where it is locked by anover-centre locking lever.